Certain known wind power turbines comprise a nacelle; a rotary assembly fitted to the nacelle to rotate about an axis of rotation; and at least one bearing or bearing assembly between the nacelle and the rotary assembly. The bearing or bearings in the bearing assembly are normally rolling bearings, which are subject to wear and must eventually be changed. Changing the bearing or bearing assembly is a complicated, painstaking job, which calls for dismantling part of the wind power turbine and invariably involves a good deal of downtime. It is also a dangerous operation, in view of the weight of the bearing and the component parts supported by it, which is directly proportional to the size of the wind power turbine.
European Patent Application No. 1,772,624 A2 describes a method of removing a bearing assembly from a wind power turbine, and which, in addition to dismantling the bearing assembly from the rotary assembly and the nacelle, also comprises manipulating the bearing assembly inside the nacelle, along and crosswise to the axis of rotation, as shown in FIG. 7 of this European Patent Application. As stated, this is a painstaking job, which is made even harder by being performed in the confined space inside the nacelle.
The same also applies to the wind power turbine described in German Patent Application No. 10 2004 028 746 A1, which calls for a similar procedure to change a single bearing.